1. Field of the Invention
The present invention relates in general to clamps. It specifically relates to a clamp for securing a vehicle draw bar and a receiver hitch with minimal relative movement therebetween. The clamp of the present invention can be used in various applications beside vehicles, including but not limited to any application where two tubes and/or bars are telescopically connected.
2. Background Art
Sport Utility Vehicles (SUV) have become quite popular, and many SUV are capable of being fitted with a draw bar incorporating a receiver hitch. Receiver hitches are generally designed to tow a non-motorized wheeled vehicle, such as a boat and/or trailer, behind a motorized vehicle. Other devices can be secured to a vehicle for the purpose of hauling several kinds of cargo. For example, roof top style cargo carriers are known to accommodate luggage, bicycles, and skis. However, lifting the cargo can be difficult, if not impossible without a ladder or some other mechanism to increase the range of the user's height. Access to the cargo is cumbersome and the mounting hardware does not lend itself to convenient installation and dismantling. Also, low height clearances may present some concern.
Several types of carrying devices which utilize the receiver hitch are available. However, these devices are designed with limited functions and for specialized purposes, and are not adaptable to accommodate a multitude, or a wide variety of cargo or accessories. For instance, a carrying device designed to carry bicycles is not readily adaptable, if at all, to accommodate luggage. As a result, the user, and more specifically the consumer, has to acquire several carrying devices to haul various types of cargo and accessories.
In some instances the support structure employed is one and the same with the carrying device. U.S. Pat. No. 5,067,641 to Johnson et al. describes a support structure which is incorporated with the carrying device, for the purpose of carrying bicycles. U.S. Pat. No. 5,038,983 to Tomososki et al., describes a support structure and a carrying tub that form integral units, and which are designed to carry only the content of the tub. The support structure in U.S. Pat. No. 4,635,835 to Cole is designed solely for transporting "All Terrain" vehicles. U.S. Pat. No. 5,145,308 to Vaughn is designed mainly for supporting a platform to haul a motorcycle.
A number of devices which use the vehicle bumper and/or bumper mounting brackets are used as a mounting point, as exemplified in U.S. Pat. No. 5,269,446 to Biehm. Vehicle manufacturers have integrated the bumpers into the vehicle design and attachment to integrated bumpers and/or access to the bumper mounting hardware can be very limited and in some cases impossible.
Also, in recent years, the auto/truck bumper design incorporates plastic or composite materials rather than steel. Sufficient weight bearing characteristics are critical. It is known that many bumpers and bumper mounting hardware are not structurally capable of handling significant weight loads safely. In addition, passenger safety can be affected if bumper safety design is compromised by adding affixments to the bumper or the bumper mounting points.
Additionally, ground clearance at the rear of the vehicle is crucial. Extension of the horizontal plane of the receiver hitch behind the vehicle can damage the carrying device and/or the cargo when a load is placed on the carrying device. Safety issues arise, with the vehicle in motion, if the carrying device collides with an obstruction or some other roadway obstacle. Also, with a load at a lower horizontal plane, user safety is compromised by lifting heavy objects from the carrying device.
Furthermore, conventional devices are installed in a fixed position, and significantly limit access to the rear of the vehicle. The cargo and/or the carrying device must be removed for the rear of the vehicle to become accessible. Yet another limitation of the conventional devices is that the carrying device remains in one fixed position when not in use.
Such exemplary conventional devices are illustrated in the following references:
U.S. Pat. No. 5,219,105 to Kravitz, PA1 U.S. Pat. No. 5,145,308 to Vaughn, PA1 U.S. Pat. No. 5,137,411 to Eul et al., PA1 U.S. Pat. No. 5,122,024 to Stokes, PA1 U.S. Pat. No. 5,067,641 to Johnson et al., PA1 U.S. Pat. No. 5,011,361 to Peterson, PA1 U.S. Pat. No. 4,971,509 to Sechovec, PA1 U.S. Pat. No. 4,938,399 to Hull et al., PA1 U.S. Pat. No. 4,934,894 to White, PA1 U.S. Pat. No. 4,915,276 to Devito, PA1 U.S. Pat. No. 4,813,584 to Wiley, PA1 U.S. Pat. No. 4,741,660 to Kent, PA1 U.S. Pat. No. 4,640,658 to Webb, Jr., PA1 U.S. Pat. No. 4,635,835 to Cole, and PA1 U.S. Pat. No. 1,849,046 to Arndt.
Rattling between a vehicle draw bar and a receiver hitch is a persistent concern for the industry. Typically, a square draw bar or tube is sized to fit and to be inserted into a receiver hitch, which is also a square tube. The draw bar and the receiver hitch are not generally manufactured to exacting tolerances, which allows ease of installation and removal by the user. The two pieces are maintained in position relative to one another by way of a locking pin that passes through transversely aligned pairs of holes in both pieces.
When a draw bar is utilized to tow a trailer, for example, swaying motion as well as side to side movement, can occur when the vehicle is moving over a road surface, causing the draw bar to shift within the receiver hitch and resulting in significant "banging" or vibration. When this occurs, the result can be quite alarming to the driver of the towing vehicle. If the vibration or "banging" is severe enough, damage could result to the draw bar, receiver hitch and/or locking pin, and other vehicle control problems could develop. A similar vibration or "banging" condition occurs when accessories, such as bike or ski mounts, or cargo/accessory carriers are inserted into the receiver hitch.
Over the years, different configurations have been designed to eliminate "rattling" between the receiver hitch and the draw bar. One attempted solution is illustration in U.S. Pat. No. 5,593,172 to Breslin, which describes a collar that surrounds the receiver hitch and draw bar combination which is "pinned" together by way of screws that press against the exterior walls of the receiver hitch and draw bar tubes. Another attempted solution is described in U.S. Pat. No. 4,050,714 to Epp, wherein two "plates" surround the draw bar tube. Two "rectangular portions" are affixed to the draw bar tube and, by way of a series of nuts and bolts, a force is applied to move the draw bar away from the receiver hitch in a direction parallel to the longitudinal axis of the hitch.
Other clamps are described in the following references:
U.S. Pat. No. 5,449,101 to Van Dusen, shows a rack carrier mounted into a receiver hitch which incorporates a bolt that keeps the rack from "rattling" in the receiver hitch;
U.S. Pat. No. 5,344,175 to Speer, shows a spring loaded pin that eliminates movement between the receiver hitch and the trailer hitch;
U.S. Pat. No. 5,333,888 to Ball, illustrates a wedge that eliminates play between the trailer hitch and the receiver hitch;
U.S. Pat. No. 5,025,932 to Jay, shows a bicycle rack and a carrier that includes a bolt used to minimize movement between the bicycle rack and the receiver hitch;
U.S. Pat. No. 4,072,257 to Hall, shows a load carrying device that includes many parts attached to the load carrying apparatus to assist in minimizing movement;
U.S. Pat. No. 2,763,498 to Vaugoyeau, shows a means of taking up play in vehicle couplings constituted by between hooks and rings; and
U.S. Pat. No. 1,875,969 to Weiss, relates to a drawbar apparatus for trailers.
However, none of these conventional clamps combines all the following features and advantages: simplicity, effectiveness, extensive use of standard hardware, and minimum fabrication.